Voltage Level Detector (CB22135E)

We found this circuit in an English documentation from the 80's. Transistors are general-purpose types.

12V x360mA Regulator (CB8823E)
This circuit is from Philips' 70s documentation. Transistors can be replaced by modern...
Astable Timer 555 (CB20682E)
This circuit was obtained in a Hands-On Electronics from the 90's. The circuit turns on one LED at...
Power Sypply for transistors (CB23574E)
This simple unregulated circuit was found in a Radio Electronics from June 1964. Note that the...